Nicolas Sarkozy is preparing to move to London to set up a billion pounds plus investment fund, it was claimed today.

If the move goes ahead, the controversial Frenchman will become the latest to escape a potential top tax rate of 75 per cent in his home country.

He and his former supermodel third wife Carla Bruni-Sarkozy would be likely to settle in an affluent district like South Kensington – so becoming the most high profile Gallic celebrity couple in the city.

But the former president is under investigation for corruption in France, and if he does cross the Channel there will be outrage.

Details of the planned move were uncovered during a raid by fraud police on Sarkozy’s Paris mansion last June.

It came within weeks of Mr Sarkozy losing his immunity against prosecution after being defeated by Socialist rival Francois Hollande in the May presidential election.

Now the hugely respected investigative news site Mediapart reports that the ‘first draft’ of Mr Sarkozy’s London project was found by detectives examining his computer files.

A judge has since made Sarkozy an assisted witness in the so-called Bettencourt Affair, in which he is accused of using illegal cash from France’s richest woman to fund his 2007 election campaign.

Mr Sarkozy is said to have taken the money from Liliane Bettencourt, the I’ Oreal heiress – a claim the politician denies, but for which he could still receive a prison sentence.

He is also being investigated over numerous other funding scandals, including one linked to arms sales to Pakistan, and another in which he is said to have used millions in taxpayers’ money to pay friends to produce opinion polls while he was in office.

Mediapart suggests that the planned London move would create a ‘conflict of interest’ – not only because Sarkozy is being investigated, but because a former French president should not choose the UK as a base to make his fortune.

Bernard Arnault, the luxury goods magnate and France’s richest man who owns property in London, and Hollywood star Gerard Depardieu are among Frenchmen who have come under intense criticism for trying to escape Mr Hollande’s new tax regime.

The socialist is introducing a top tax rate of 75 per cent on anyone earning more than 1 million euros a year because he disapproves of the kind of vast profits made by speculators in places like the City of London.

Mr Sarkozy, however, is a committed capitalist, whose close friends include former Prime Minister Tony Blair, who has himself earned millions since leaving office.

The French former president’s new private equity fund would aim to raise 1 billion euros – something he hopes to achieve with the help of French entrepreneur and political advisor Alain Minc.

Mr Sarkozy has recently had meetings with numerous movers and shakers in the world of high finance during high-profile trips to places like Qatar and London. But today Mr Sarkozy played down the Mediapart reports through his aides, with one saying that they were the result of ‘intellectual constructs’.

Like Mr Blair, the former head of state has always been extremely secretive about his financial dealings, and would be unlikely to discuss a wealth fund in public.